On Mon, Dec 23, 2019 at 8:40 AM Amir Goldstein <amir73il@xxxxxxxxx> wrote:
>
> The WARN_ON() that child entry is always on overlay st_dev became wrong
> when we allowed this function to update d_ino in non-samefs setup with
> xino enabled.
>
> It is not true in case of xino bits overflow on a non-dir inode.
> Leave the WARN_ON() only for directories, where assertion is still true.
>
> Fixes: adbf4f7ea834 ("ovl: consistent d_ino for non-samefs with xino")
> Cc: <stable@xxxxxxxxxxxxxxx> # v4.17+
> Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
> ---
>
Miklos,
If you have time, please send this one to Linus for v5.5.
It is a simple fix and the only one causing failure in the new xfstests [1]
that I posted.
Thanks,
Amir.
[1] https://lore.kernel.org/fstests/20191230141423.31695-1-amir73il@xxxxxxxxx/
>
> fs/overlayfs/readdir.c | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c
> index 47a91c9733a5..7255e6a5838f 100644
> --- a/fs/overlayfs/readdir.c
> +++ b/fs/overlayfs/readdir.c
> @@ -504,7 +504,13 @@ static int ovl_cache_update_ino(struct path *path, struct ovl_cache_entry *p)
> if (err)
> goto fail;
>
> - WARN_ON_ONCE(dir->d_sb->s_dev != stat.dev);
> + /*
> + * Directory inode is always on overlay st_dev.
> + * Non-dir with ovl_same_dev() could be on pseudo st_dev in case
> + * of xino bits overflow.
> + */
> + WARN_ON_ONCE(S_ISDIR(stat.mode) &&
> + dir->d_sb->s_dev != stat.dev);
> ino = stat.ino;
> } else if (xinobits && !OVL_TYPE_UPPER(type)) {
> ino = ovl_remap_lower_ino(ino, xinobits,
> --
> 2.17.1
>
